1 | /* |
2 | * Copyright 2017 The OpenSSL Project Authors. All Rights Reserved. |
3 | * |
4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
5 | * this file except in compliance with the License. You can obtain a copy |
6 | * in the file LICENSE in the source distribution or at |
7 | * https://www.openssl.org/source/license.html |
8 | */ |
9 | |
10 | #include <stdio.h> |
11 | #include "internal/cryptlib.h" |
12 | #include "dh_local.h" |
13 | #include <openssl/bn.h> |
14 | #include <openssl/objects.h> |
15 | #include "crypto/bn_dh.h" |
16 | |
17 | static DH *dh_param_init(const BIGNUM *p, int32_t nbits) |
18 | { |
19 | DH *dh = DH_new(); |
20 | if (dh == NULL) |
21 | return NULL; |
22 | dh->p = (BIGNUM *)p; |
23 | dh->g = (BIGNUM *)&_bignum_const_2; |
24 | dh->length = nbits; |
25 | dh->dirty_cnt++; |
26 | return dh; |
27 | } |
28 | |
29 | DH *DH_new_by_nid(int nid) |
30 | { |
31 | switch (nid) { |
32 | case NID_ffdhe2048: |
33 | return dh_param_init(&_bignum_ffdhe2048_p, 225); |
34 | case NID_ffdhe3072: |
35 | return dh_param_init(&_bignum_ffdhe3072_p, 275); |
36 | case NID_ffdhe4096: |
37 | return dh_param_init(&_bignum_ffdhe4096_p, 325); |
38 | case NID_ffdhe6144: |
39 | return dh_param_init(&_bignum_ffdhe6144_p, 375); |
40 | case NID_ffdhe8192: |
41 | return dh_param_init(&_bignum_ffdhe8192_p, 400); |
42 | default: |
43 | DHerr(DH_F_DH_NEW_BY_NID, DH_R_INVALID_PARAMETER_NID); |
44 | return NULL; |
45 | } |
46 | } |
47 | |
48 | int DH_get_nid(const DH *dh) |
49 | { |
50 | int nid; |
51 | |
52 | if (BN_get_word(dh->g) != 2) |
53 | return NID_undef; |
54 | if (!BN_cmp(dh->p, &_bignum_ffdhe2048_p)) |
55 | nid = NID_ffdhe2048; |
56 | else if (!BN_cmp(dh->p, &_bignum_ffdhe3072_p)) |
57 | nid = NID_ffdhe3072; |
58 | else if (!BN_cmp(dh->p, &_bignum_ffdhe4096_p)) |
59 | nid = NID_ffdhe4096; |
60 | else if (!BN_cmp(dh->p, &_bignum_ffdhe6144_p)) |
61 | nid = NID_ffdhe6144; |
62 | else if (!BN_cmp(dh->p, &_bignum_ffdhe8192_p)) |
63 | nid = NID_ffdhe8192; |
64 | else |
65 | return NID_undef; |
66 | if (dh->q != NULL) { |
67 | BIGNUM *q = BN_dup(dh->p); |
68 | |
69 | /* Check q = p * 2 + 1 we already know q is odd, so just shift right */ |
70 | if (q == NULL || !BN_rshift1(q, q) || !BN_cmp(dh->q, q)) |
71 | nid = NID_undef; |
72 | BN_free(q); |
73 | } |
74 | return nid; |
75 | } |
76 | |